Enhanced photocatalytic activities of visible light-responsive Ag3PO4-GO photocatalysts for oxytetracycline hydrochloride degradation

Abstract

A series of Ag3PO4-GO-X (X = 1, 2 and 3) photocatalysts, with different graphene oxide (GO) content, were successfully prepared by chemical precipitation. Oxytetracycline hydrochloride (OTC) was selected as target compound to assess the photocatalytic efficiency of the Ag3PO4-GO -X composites. The characteristics of the photocatalysts were studied by SEM, TEM, XRD, XPS, UV–vis DRS, Raman spectroscopy and photoelectrochemical measurements. The enhanced photocatalytic mechanism of Ag3PO4-GO composite was proposed. Results indicated that Ag3PO4 was successfully integrated with GO. The visible light absorption range of Ag3PO4-GO composites effectively was expanded more than pure Ag3PO4. The adsorption capacity of the catalyst for OTC was also greatly enhanced. 99.24 % of OTC was removed in 60 min visible light irradiation, as the content of GO was 6% in the composite. After being reused five times, the photocatalytic degradation efficiency still reached 94.77 %. Reactive species of h+ were the main participants in oxidizing OTC, meanwhile •O2− and OH• contributed to the degradation process. This work provided a simple and effective approach to prepare Ag3PO4-GO composites. The results suggested that the addition of GO increased the electron-hole pairs separation efficiency of Ag3PO4 and improved the photocatalytic degradation activity of Ag3PO4 The as-prepared Ag3PO4-GO composites displayed promising effects in the photocatalytic removal of refractory organic pollutants as a visible light-responsive photocatalyst.